RUI: Characterization of Proteins Interacting with PKABA1 in Abscisic Acid Signaling

植物激素脱落酸(ABA)是一种重要的信号分子，无论是在正常的生长发育过程中，还是在响应干旱等环境胁迫过程中都是重要的信号分子。对ABA的许多反应涉及特定基因表达的变化。一些基因受到ABA的刺激，而另一些基因则受到抑制。在谷物中，蛋白激酶PKABA1在ABA信号通路中扮演中间体的角色。具体地说，PKABA1的作用导致了ABA诱导的几个种子表达基因的抑制。为了了解PKABA1在ABA信号中的确切作用，有必要确定与PKABA1协同作用的蛋白质。最近发现了两种这样的蛋白质，TaABF和TaWD40，它们将成为这个项目的焦点。TaABF属于ABF转录因子家族，这是一种与DNA序列结合并调节基因活性的蛋白质。为了确定TaABF在对ABA反应的细胞中的生物学作用，我们将诱导大麦糊粉细胞同时过度生产和降低TaABF，并观察其对ABA信号转导的影响。此外，PKABA1和TaABF之间的相互作用将通过结合分析来表征，并将评估PKABA1磷酸化TaABF的能力。为了证实TaABF作为一种转录因子调节基因活性，我们将对其DNA结合特性进行分析。TaWD40的生物学作用将在类似于为TaABF建议的实验中进行评估。更广泛的影响：这项工作将有助于更好地理解植物如何对ABA做出反应。这些知识将有助于今后制定一些农业问题的实际解决方案，如保护作物免受田间胁迫、谷类作物的收割前发芽，以及控制种子休眠严重的杂草物种。该项目将通过吸引本科生参与，为教育做出贡献。所使用的技术和从研究计划中获得的结果将被纳入到国际学生联合会教授的课程中，因此许多没有直接参与该项目的学生也将受益。国际学生联合会广泛参与生物学入门课程和少数族裔学生辅导计划，将招收传统上在科学界代表性较低的群体的学生。

The plant hormone abscisic acid (ABA) is an important signaling molecule, both during normal processes of growth and development and in responding to environmental stresses such as drought. Many of the responses to ABA involve changes in the expression of particular genes. Some genes are stimulated by the presence of ABA, while other genes are repressed. In cereal grains, the protein kinase, PKABA1, acts as an intermediate in the ABA-signaling pathway. Specifically, the action of PKABA1 brings about an ABA-induced repression of several seed-expressed genes. To understand the precise role of PKABA1 in ABA-signaling, it is necessary to identify proteins that act in concert with PKABA1. Two such proteins, TaABF and TaWD40, have recently been identified and will be the focus of this project.TaABF belongs to the ABF family of transcription factors, a type of protein that binds to DNA sequences and regulates gene activity. To confirm the biological role of TaABF in cells that are responding to ABA, aleurone cells of barley grains will be induced to both overproduce and underproduce TaABF, and the effects on ABA signaling will be observed. In addition, the interaction between PKABA1 and TaABF will be characterized by binding assays, and the ability of PKABA1 to phosphorylate TaABF will be assessed. To confirm that TaABF functions as a transcription factor in modulating gene activity, its DNA-binding properties will be assayed. The biological role of TaWD40 will be assessed in experiments similar to those proposed for TaABF. Broader Impacts: This work will lead to a better understanding of how plants respond to ABA. Such knowledge will support the future development of practical solutions to a number of agricultural problems, such as protection of crop plants from stresses in the field, preharvest sprouting of cereals, and the control of weedy species with strong seed dormancy. The project will contribute to education by involving undergraduate students. The techniques used and the results obtained from the research program will be incorporated into courses taught by the PI so that many students not directly involved in the project will also benefit. The PI's extensive involvement with Introductory Biology courses and with programs for the mentoring of minority students will lead to recruitment of students from groups traditionally underrepresented in the sciences.